Restrictions on the quantity of goods that can enter a country

quota

tariffs

boycotts

embargos

Quota;

Explanation:

To protect local manufacturers from unfair competition from foreign goods,  governments restrict the quantities of imports. Imposing these restrictions is the application of a quota policy.

Quota places a limit on the maximum quantity of a particular product that business people can import. Quota aims to enable domestic producers to manufacture and sell their products in the country at reasonable prices. Increased domestic production creates employment and stimulates economic developments in the country.

Quota may also be used to regulate the volume of trade between a country and its trading partners.

answer; by looking at total product,marginal product,and changes in both after changes in inputs